Sadaharu (定春 Sadaharu) is a member and a pet of the Yorozuya, but is equivalent to being their mascot. Kagura usually takes care of him, but Sakata Gintoki sometimes has to walk him, much to his dismay. He is also savior of the earth, preventing an invasion of alien cockroaches in Episode 29.
Sadaharu was originally an Inugami (aka Dog God) of destruction and attack, watched over by the Priestess Sisters Ane and Mone. Sadaharu, along with his counterpart in charge of protection and defense, Komako, were entrusted with guarding the 龍脈 ryuumyaku aka Dragon's Pulse at the 龍穴 ryuuketsu aka Dragon's Lair on Earth but when the Amanto came, they built the Space Terminal over the Dragon's Pulse thus leaving Sadaharu and the sisters without a job. As time passed expenses became too high and they were forced to give Sadaharu away, and so they left him in the custody of the Yorozuya whom he has stayed with ever since.
Appearance
He is a quite large white-furred dog with a red collar. He has Black/Dark Gray eyes, he is about 170 cm (5' 7") tall when seated and weighs about 300 kg (661 lb).
Throughout the series he is seen wearing various disguises and has been shown in different styles for gags.
Sadaharu has the tendency of biting people's head. A list of head-bitten victims can be found here.
Strength & Abilities
When he is fed with strawberries and milk (Strawberry Milk), he can grow even larger and transform into a ferocious horned monster. To turn him back to his normal self again, the Yorozuya had to team up with Ane 阿音 and Mone 百音, and play catch using a baseball loaded with the power of genriki (genriki are powers attained through ascetic practices) to trace a five-pointed star charm. Komako (狛子) is his opposite half, a mini-version of Sadaharu, with the same ability to transform into a ferocious mini-horned version.
Relationship
Sakata Gintoki: Although at first Sadaharu keeps biting Gintoki, he learned to hold back his habit. Gintoki usually takes Sadaharu for walks, and the two learned to like each other. Sadaharu also seems to be the only one in the group that recognizes Gintoki when no one else does, like when Sakata Kintoki took over the Yorozuya, and in the second movie, Be Forever Yorozuya, seeing through Gintoki's disguise as "Chin".
Kagura picked Sadaharu outside Yorozuya and she cares for him and refused to abandon him. In Inugami arc, although when Kagura questioned Sadaharu usual feeling to her, he claims that she was ranked 7th in the Jump popularity poll, he changed to his inugami form after Kagura injured.
Shimura Shinpachi: Shinpachi plays more of the mother role of taking care of the Sadaharu, Shinpachi usually feeds him or clean up his mess. Sadaharu observes Shinpachi and he claims to pity him because he has no speciality besides from idol otaku.
Elizabeth: They would fight for the role of Gintama Mascot and the popular character and fight together (they slap Sarutobi and Tsukuyo).
Story
He was found outside Yorozuya by Kagura in Episode 10
Sadaharu was feeling bad so they took him to a veterinary. He had eaten a human-sized doll and he puked it. Katsura appeared and started to talk with Kagura. He said that he came here to show Elizabeth to a doctor. Suddenly, they heard a doctor talking with someone about a dying dog and its dying master.
They escaped with the dog and went out to drink something. Kintarou introduced himself as a planet eater and started to how he came to the earth. Kagura got bored and wanted to go home, but Katsura convinced her to bring Kintarou to his master. They all started to ride on Sadaharu, and go to Kintarou’s master, but the cats, planet pukers, started to pursue them. Katsura tried to convince them and when he failed, he jumped towards them to draw their attention, but the cats didn’t look at him and fell to the ground. Kagura used Kintarou as a bait and lots of cats caught him, but Kintarou used his ultimate move Candlelight Last Sparkling, and managed to throw all of the planet pukers.
They took shelter in a park. Kintarou had exhausted himself so he only had five candles left in his life gauge, but Kagura switched one of them with her firework, but it melted one of the candles. Sadaharu extinguished it by pissing on them. Only three candles were left. The old man suddenly appeared in front of them with a leash in his hand and shocked Kintarou. Cats found Kintarou, but Kagura stopped them. Kintarou caught the leash and started to go with the old man.
Kagura, with Sadaharu, later came to the place that old man and Kintarou died and left some flowers for them.
Sadaharu and Tama were the ones who are not affected by the sound waves that can release Gintoki from the memories of the Kabuki district, caused by Kintoki.
